This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. 1. Aim 1: Impaired development of working memory, inhibition, and metacognitive skills is directly related to the severity of acute CHI and the volume of residual prefrontal lesions. Development of working memory, inhibition, and metacognitive skills is more adversely affected by severe CHI occurring before age 9 years as compared to the outcome of severe CHI occurring in older children. 2. Aim 2: Problems in discourse processing, scholastic achievement, and adaptive skills are directly related to deficient development of working memory, inhibition, and metacognitive skills following head injury in children. 3. Aim 3: Children whose inhibition and metacognitive skills are impaired following CHI are at increased risk for developing attention-deficit/hyperactivity disorder (ADHD), and related externalizing disorders (i.e., Oppositional-Defiant and Conduct Disorders). Posttraumatic internalizing disorders are related to preinjury internalizing disorders and the psychological stress associated with the injury. The presence of prefrontal and/or basotemporal lesions, history of a preinjury psychiatric disorder in the child or parents, and adverse psychosocial environment contribute to the increased risk of developing a psychiatric disorder following CHI.